<style>
    *{padding: 0;margin: 0;}
    html,body{
        background-color: #000;
    }
</style>
<body>
    <div class="xuetiao" style="width: 100px;height: 30px;background-color: #fff;border: 1px solid red;">
        <div class="xue" style="width: 100px;height: 30px;background-color: red;"></div>
    </div>
    <script src="./血条.js">xuetiao()</script>
    
</body>
